16. The Dynamic Tower

Each of the 80 floors in the world's first moving skyscraper  with offices and a hotel, topped by apartments  will rotate 360 degrees, all at different speeds. Designed by Italian architect David Fisher and located in Dubai (another is planned for Moscow), the prefab, wind-powered tower will cost an estimated $700 million. The residences will sell for $3.7 million to $36 million. The building should be completed in 2010.